[PATCH v6 1/3] EDAC: Remove fake_inject debugfs interface

[Yazen Ghannam]

The interface has a potential race condition between a real and fake
error when updating the memory controller's error descriptor.

There doesn't seem to be an active user base for this interface, so
remove it.

Reported-by: sashiko-bot <sashiko-bot@xxxxxxxxxx>
Closes: https://sashiko.dev/#/patchset/20260518160716.171578-1-yazen.ghannam%40amd.com
Suggested-by: Borislav Petkov <bp@xxxxxxxxx>
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
Link: https://lore.kernel.org/linux-edac/20260611012336.GHaioOGB0NBxv5BZXS@fat_crate.local/
---
 drivers/edac/debugfs.c | 65 +-----------------------------------------
 include/linux/edac.h   |  3 --
 2 files changed, 1 insertion(+), 67 deletions(-)

diff --git a/drivers/edac/debugfs.c b/drivers/edac/debugfs.c
index 8195fc9c9354..447d0c620082 100644
--- a/drivers/edac/debugfs.c
+++ b/drivers/edac/debugfs.c
@@ -1,50 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
-#include <linux/string_choices.h>
-
 #include "edac_module.h"
 
 static struct dentry *edac_debugfs;
 
-static ssize_t edac_fake_inject_write(struct file *file,
-				      const char __user *data,
-				      size_t count, loff_t *ppos)
-{
-	struct device *dev = file->private_data;
-	struct mem_ctl_info *mci = to_mci(dev);
-	static enum hw_event_mc_err_type type;
-	u16 errcount = mci->fake_inject_count;
-
-	if (!errcount)
-		errcount = 1;
-
-	type = mci->fake_inject_ue ? HW_EVENT_ERR_UNCORRECTED
-				   : HW_EVENT_ERR_CORRECTED;
-
-	printk(KERN_DEBUG
-	       "Generating %d %s fake error%s to %d.%d.%d to test core handling. NOTE: this won't test the driver-specific decoding logic.\n",
-		errcount,
-		(type == HW_EVENT_ERR_UNCORRECTED) ? "UE" : "CE",
-		str_plural(errcount),
-		mci->fake_inject_layer[0],
-		mci->fake_inject_layer[1],
-		mci->fake_inject_layer[2]
-	       );
-	edac_mc_handle_error(type, mci, errcount, 0, 0, 0,
-			     mci->fake_inject_layer[0],
-			     mci->fake_inject_layer[1],
-			     mci->fake_inject_layer[2],
-			     "FAKE ERROR", "for EDAC testing only");
-
-	return count;
-}
-
-static const struct file_operations debug_fake_inject_fops = {
-	.open = simple_open,
-	.write = edac_fake_inject_write,
-	.llseek = generic_file_llseek,
-};
-
 void __init edac_debugfs_init(void)
 {
 	edac_debugfs = debugfs_create_dir("edac", NULL);
@@ -57,29 +16,7 @@ void edac_debugfs_exit(void)
 
 void edac_create_debugfs_nodes(struct mem_ctl_info *mci)
 {
-	struct dentry *parent;
-	char name[80];
-	int i;
-
-	parent = debugfs_create_dir(mci->dev.kobj.name, edac_debugfs);
-
-	for (i = 0; i < mci->n_layers; i++) {
-		sprintf(name, "fake_inject_%s",
-			     edac_layer_name[mci->layers[i].type]);
-		debugfs_create_u8(name, S_IRUGO | S_IWUSR, parent,
-				  &mci->fake_inject_layer[i]);
-	}
-
-	debugfs_create_bool("fake_inject_ue", S_IRUGO | S_IWUSR, parent,
-			    &mci->fake_inject_ue);
-
-	debugfs_create_u16("fake_inject_count", S_IRUGO | S_IWUSR, parent,
-			   &mci->fake_inject_count);
-
-	debugfs_create_file("fake_inject", S_IWUSR, parent, &mci->dev,
-			    &debug_fake_inject_fops);
-
-	mci->debugfs = parent;
+	mci->debugfs = debugfs_create_dir(mci->dev.kobj.name, edac_debugfs);
 }
 
 /* Create a toplevel dir under EDAC's debugfs hierarchy */
diff --git a/include/linux/edac.h b/include/linux/edac.h
index e6b4e51130e5..f7a8218f9cc0 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -598,9 +598,6 @@ struct mem_ctl_info {
 	int op_state;
 
 	struct dentry *debugfs;
-	u8 fake_inject_layer[EDAC_MAX_LAYERS];
-	bool fake_inject_ue;
-	u16 fake_inject_count;
 
 	/*
 	 * Memory Controller hierarchy
-- 
2.53.0